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MIS 5212.001 Week 12 Site:

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1 MIS 5212.001 Week 12 Site: http://community.mis.temple.edu/mis5212sec001s15/ http://community.mis.temple.edu/mis5212sec001s15/

2  In the news  Presentation (1)  WEP  Revisit Kismet  Introduction to Aircrack  Attacking WEP  WPA-PSK  Next Week 2MIS 5212.001

3  Submitted  http://thehackernews.com/2015/04/hack-delete- youtube-video.html http://thehackernews.com/2015/04/hack-delete- youtube-video.html  http://www.wired.com/2015/04/ny-cops-used- stingray-spy-tool-46-times-without-warrant/ http://www.wired.com/2015/04/ny-cops-used- stingray-spy-tool-46-times-without-warrant/  http://www.darkreading.com/risk/7-bugs- breaches-and-compromises-to-rock-2015-(so- far)/d/d-id/1319672 http://www.darkreading.com/risk/7-bugs- breaches-and-compromises-to-rock-2015-(so- far)/d/d-id/1319672  http://thehackernews.com/2015/04/anonymous- cyber-attack-israel.html http://thehackernews.com/2015/04/anonymous- cyber-attack-israel.html MIS 5212.0013

4  Submitted MIS 5212.0014

5  What I noted  http://krebsonsecurity.com/2015/04/revolution- crimeware-emv-replay-attacks/ http://krebsonsecurity.com/2015/04/revolution- crimeware-emv-replay-attacks/  http://www.theregister.co.uk/2015/04/07/mozilla _crypto_encryption_snafu_pull/ http://www.theregister.co.uk/2015/04/07/mozilla _crypto_encryption_snafu_pull/  http://www.theregister.co.uk/2015/04/07/uberpo pular_crypto_app_uses_xor_and_nothing_else_hack er_says/ http://www.theregister.co.uk/2015/04/07/uberpo pular_crypto_app_uses_xor_and_nothing_else_hack er_says/  http://www.securityweek.com/google-lets-smtp- certificate-expire http://www.securityweek.com/google-lets-smtp- certificate-expire  https://securityledger.com/2015/04/research-iot- hubs-expose-connected-homes-to-hackers/ https://securityledger.com/2015/04/research-iot- hubs-expose-connected-homes-to-hackers/ MIS 5212.0015

6 6

7  Basic encryption for wireless networks  Specified in IEEE 802.11-1997  Required a minimum 40-bit key, usually set at 104-bit  Uses RC-4 encryption  Applied only to data frames (Payload)  Still widely used, especially on older gear MIS 5212.0017

8  Described as 64 or 128 bit  Reality is 40 or 104  The pre-shared key (Not the same as WPA- PSK) is either 5 or 13 bytes  Initialization vector is transmitted with each packet  IV and key are concatenated to create a per packet key  IV is not a secret!  Four possible keys, index 0-3 MIS 5212.0018

9  One bit field in the frame control field  Called by a number of different names  WEP bit  Privacy bit  Secure bit  With this bit set, the receiving station expects to see a four byte WEP header immediately following the 802.11 header  Also expects to see a four byte trailer immediately following the payload or data portion MIS 5212.0019

10  The four byte header is also the initialization vector or IV along with the index number to designate which WEP key was used  Again, this was used with the WEP key to encrypt the data packet  The four byte trailer is the Integrity Check Value or ICV  This function similar to a CRC check to protect against packet modification MIS 5212.00110

11  Stream cypher  One byte at a time  100 bytes of plaintext = 100 bytes of cypher text + eight bytes of WEP overhead  Requires a unique key (No re-use)  Recall: concatenated from IV and shared secret  Uses a pseudo randomization function referred to as PRGA (Pseudo-random generation algorithm )  PRGA is XOR’d with the plaintext  Recall article on XOR from in the news MIS 5212.00111

12  Poor  Key selection  Message integrity check  Initialization Vector (too short)  No replay protection  Challenge response reveals PRGA  Key is reversible from cypher test (XOR) MIS 5212.00112

13  Restricted to 5 or 13 character pre-shared key  Reduced key efficiency to 2 24  Users often use dictionary words MIS 5212.00113

14  Weak IV selection leads to key recovery  Known plaintext reveals key information  First two bytes of WEP payload are mandated by 802.11 header spec (0xAA 0xAA)  Once you have enough weak IVs, you can recover the key  We will look at the Aircrack-ng tool for this MIS 5212.00114

15  Pre-installed in Kali  Similar issue to Kismet, will need to launch from terminal, not from drop down  Aircrack-ng site has detailed information on installation, building from source, and use  http://aircrack-ng.org/ http://aircrack-ng.org/ MIS 5212.00115

16  Need to connect wireless card to Kali  Need to verify using iwconfig command  Then launch Kismet for a little recon  This will also force the wireless card in to monitor mode  Since StarDrive is my AP we’ll focus on it MIS 5212.00116

17  Double clicking on name gives me detail screen  Note  MAC Address  WEP bit  “Network” menu has option to close window and return to summary MIS 5212.00117

18 MIS 5212.00118

19  We found the AP we want to attack  Know Name (SSID), MAC Address (BSSID), WEP  This also had the affect of forcing wlan0 into monitor mode MIS 5212.00119

20  Lots of extras at:  http://aircrack- ng.org/doku.php?id=simple_wep_crack&Dok uWiki=6a160c439893f7cfb1e861fe023a1e9d http://aircrack- ng.org/doku.php?id=simple_wep_crack&Dok uWiki=6a160c439893f7cfb1e861fe023a1e9d  We’ll run through a few MIS 5212.00120

21  Created ARP traffic to get data faster  You do need access to wired network, so limited applicability in the wild  Used command: MIS 5212.00121

22  Running command:  This will create log file capture*.cap for further analysis MIS 5212.00122

23  Once enough data has been collected, run  aircrack-ng output*.cap  If you don’t have enough data you will see MIS 5212.00123

24  Eventually, with enough IVs you can get to this: MIS 5212.00124

25  Recall, WPA introduced TKIP  WPA2 introduced CCMP and kept TKIP  Both work with both personal and enterprise  Personal – PSK, Enterprise 802.1x  WPA and WPA2 very similar for PSK MIS 5212.00125

26  PSK – Pre-Shared Key  KEK – Key Encryption Key  PMK – Pairwise Master Key – Comes from PSK or EAP method  PTK – Pairwise Temporal Key  Two MIC keys (RX and TX  EAPOL Key Encryption Key  EAPOL Key Confirmation Key MIS 5212.00126

27  PMK is 256 bits in length  PMK is derived using passphrase, ssid, and ssid length information  Hashed 4096 times using HMAC-SHA1  This means process cannot be reversed to extract passphrase MIS 5212.00127

28  Combines MAC of STA and AP with STA and AP nonces  Update nonces generate fresh keys  Uses PMK as additional input (Re: Key) along with the phrase “Pairwise Key Expansion” and combines with above and hashed w/ SHA1 to generate a PTK Note: Nonce is a random value generated by both STA and AP MIS 5212.00128

29  PTK is 384/512 bits in length  First 16 bytes – HMAC MIC key  Next 16 – EAPOL-Key KEK  Next 16 – Temporal Encryption Key  Next 8 – TX TKIP Michael (MIC) Key  Next 8 – RX TKIP Michael (MIC) Key MIS 5212.00129

30 Step 1ANonce, start new PTK negotion SNonce, MIC of Frame 2Step 2 Step 3MIC of frame 3 MIC of frame 4, ready to TX/RX Step 4 MIS 5212.00130

31 MIS 5212.00131  Example  First four lines are 4-Way Handshake  Source has capture file if you want to look for yourself Source: http://mrncciew.com/2014/08/16/decrypt-wpa2-psk-using-wireshark/http://mrncciew.com/2014/08/16/decrypt-wpa2-psk-using-wireshark/

32  AP beacon frames identify capability information  Cypher suite support  Auth key management  Wireshark can filter traffic, then manual inspection can identify MIS 5212.00132

33  Example of beacon frame in wireshark  http://www.hackxcrack.es/forum/hacking- wireless/cracking-wpawpa2-con-reaver/ http://www.hackxcrack.es/forum/hacking- wireless/cracking-wpawpa2-con-reaver/ MIS 5212.00133

34  In the news  More wireless  John the Ripper  Attacking WPA-PSK  Final thoughts MIS 5212.00134

35 ? MIS 5212.00135


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